There are 100 monks eating 100 steamed buns, one big monk eating four steamed buns, and four young monks eating 1 steamed buns. How many big monks and young monks are there?

2. There are 40 oil drums, each of which is 5kg, and each of which is 2kg. The oil in all vats is 32 Jin more than that in small vats. How many barrels are there?

3. There are two piles of coal, pile A is 94 tons, and pile B 138 tons. If each pile carries 9 tons per day, how many days later will B be three times that of A?

4.

2 boxes +5 cups =23 yuan.

8 boxes +6 cups =50 yuan.

How much is a cup and a box?